This paper introduces a lightweight framework for implementing intelligent interactive systems (IIS). In particular, systems that integrate symbolic knowledge bases for reasoning, planning and rational decision-making in interactions with humans. This is done by integrating Web Ontology Language (OWL)-based reasoning and Answer Set Programming (ASP)-based planning software. In order to provide interactive user components, the framework is encompassed in a widely used game development tool, Unity. The proposed framework, UnityIIS, is the first approach for integrating OWL together with ASP in Unity. Its central functionalities for knowledge representation and knowledge revision is presented together with an example application created in the framework. A chatbot agent, embodied in Augmented Reality, is designed, following a Belief, Desire, Intention (BDI) agent model. The set of tools that the framework provides can be applied for developing IIS research prototypes as well as being an asset in teaching practices.